The following commit has been merged into the x86/entry branch of tip:
Commit-ID: f4f6b66fd8011eb5f24dec936faaa4cab2ca7ebc
Gitweb: https://git.kernel.org/tip/f4f6b66fd8011eb5f24dec936faaa4cab2ca7ebc
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 05 Mar 2020 16:09:52 +01:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 19 May 2020 16:04:07 +02:00
x86/traps: Split int3 handler up
For code simplicity split up the int3 handler into a kernel and user part
which makes the code flow simpler to understand.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Chartre <alexandre.chartre@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20200505135314.045220765@xxxxxxxxxxxxx
---
arch/x86/kernel/traps.c | 68 +++++++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 28 deletions(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 0ad12df..21c8cfc 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -568,6 +568,35 @@ exit:
cond_local_irq_disable(regs);
}
+static bool do_int3(struct pt_regs *regs)
+{
+ int res;
+
+#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
+ if (kgdb_ll_trap(DIE_INT3, "int3", regs, 0, X86_TRAP_BP,
+ SIGTRAP) == NOTIFY_STOP)
+ return true;
+#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
+
+#ifdef CONFIG_KPROBES
+ if (kprobe_int3_handler(regs))
+ return true;
+#endif
+ res = notify_die(DIE_INT3, "int3", regs, 0, X86_TRAP_BP, SIGTRAP);
+
+ return res == NOTIFY_STOP;
+}
+
+static void do_int3_user(struct pt_regs *regs)
+{
+ if (do_int3(regs))
+ return;
+
+ cond_local_irq_enable(regs);
+ do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, 0, 0, NULL);
+ cond_local_irq_disable(regs);
+}
+
DEFINE_IDTENTRY_RAW(exc_int3)
{
/*
@@ -585,37 +614,20 @@ DEFINE_IDTENTRY_RAW(exc_int3)
* because the INT3 could have been hit in any context including
* NMI.
*/
- if (user_mode(regs))
+ if (user_mode(regs)) {
idtentry_enter(regs);
- else
- nmi_enter();
-
- instrumentation_begin();
-#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
- if (kgdb_ll_trap(DIE_INT3, "int3", regs, 0, X86_TRAP_BP,
- SIGTRAP) == NOTIFY_STOP)
- goto exit;
-#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
-
-#ifdef CONFIG_KPROBES
- if (kprobe_int3_handler(regs))
- goto exit;
-#endif
-
- if (notify_die(DIE_INT3, "int3", regs, 0, X86_TRAP_BP,
- SIGTRAP) == NOTIFY_STOP)
- goto exit;
-
- cond_local_irq_enable(regs);
- do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, 0, 0, NULL);
- cond_local_irq_disable(regs);
-
-exit:
- instrumentation_end();
- if (user_mode(regs))
+ instrumentation_begin();
+ do_int3_user(regs);
+ instrumentation_end();
idtentry_exit(regs);
- else
+ } else {
+ nmi_enter();
+ instrumentation_begin();
+ if (!do_int3(regs))
+ die("int3", regs, 0);
+ instrumentation_end();
nmi_exit();
+ }
}
#ifdef CONFIG_X86_64
|